Techno-Economic Analysis

Balancing Economics and Sustainability

To be able to compete with fossil feedstock, highly efficient production of biomass-based products is required to optimize overall process economics and to minimize negative environmental impact. In order to reach reasonable production costs, a favorable economy-of-scale must be identified with scale-up data applied to a model.

At ABPDU we utilize techno-economic analyses (TEA) at different levels of rigor at various stages of the conversion process from preliminary exploration and detailed investigation to development and validation. TEA provides us with a quantitative and qualitative understanding of the impact that technology and research breakthroughs have on the financial viability of the biomass conversion strategy.

Techno-Economic Model at ABPDU

Accelerating Commercialization of Research Advances

JBEI’s wiki-based technoeconomic model simulates critical factors in the biorefinery process, enabling scientists to evaluate the real-world potential of research developments and focus on the most promising strategies. [Image courtesy JBEI]

How TEA Works

An integral tool for both research and commercial project development, TEA combines process modeling and engineering design with economic evaluation. TEA helps to assess the economic viability of a process and provides direction to research, development, investment, and policy making. It integrates well with the stage gate analysis process many private industry and R&D centers use for project development. To be fully effective, TEA requires the harnessing of detailed information drawn from multiple sources such as literature, research data, and vendor specifications.

Eliminating bottlenecks and optimizing the process is a high priority in scale-up research and TEA is a powerful tool that helps us addresses these issues. We utilize the pilot scale data and simulate the operation of a commercial scale facility. This simulation enables us to identify bottlenecks in the process and re-define the scope of future process research.

Our Techno-Economic Analysis Methodologies

Techno-Economic Models

Our models cover the following unit processes:

Feedstock handling

Biomass Deconstruction

Fermentation

Product recovery

Wastewater treatment

We integrate these units and populate the model with data generated at the ABPDU or elsewhere and identify the most expensive processes and/or material handling steps. We can also identify geographical location related restrictions that can sway the economic analysis. Once such a performing model is developed, we are able to compare it to similarly developed models for other end-to-end technology pathways. Such comparisons can guide strategic decision-making, very early on.

Process Design

Design of a conceptual process entails ideas and simple assumptions drawn from literature and R&D data combined with collaboration across our engineering team to identify technical and economic hurdles.

Mass and Energy Balance

We use measured data from lab and scale-up studies to obtain near 100% mass balance closures, which are incorporated into the TEA model. Energy balance can also be pursued at this stage. Applying mass yields along with measured calorific values from biomass to fuels and chemicals (bomb calorimetry of solid and liquid samples) provides measured energy yields from the pathway. These energy yields along with energy consumption from each of the processes allow us to establish energy balance. Incorporating mass and energy balance into TEA ensures that the technology pathway is commercially feasible.

Cost Estimations

Along with mass and energy balance, scale-up data provides us an opportunity to identify commercial-scale equipment through TEA. Aspen Plus® and SuperPro® both provide options of equipment models closest the utilized equipment specifications. The TEA model estimates equipment cost, capital investment and its depreciation, and operating expenditure. By calculating a discounted cash flow rate of return, we can identify additional barriers for scale-up and re-focus research and development in those particular areas.

Profitability Analysis

Our profitability analysis factors in several pieces of information, such as annual production, unit production cost, revenues, gross margin, profit, return on investment, payback time, and capital investment.

Sensitivity Analysis

Sensitivity analyses are extremely useful in dealing with bottlenecks and identifying target yields and production scales. It allows for comparison of the magnitude of impact on process economics when varying process parameters for anticipated restrictions. Once a model for the entire process is developed, the tool can be used to carry out sensitivity analyses with respect to selected design variables.

Related Papers and Publications

ABPDU has been developing and validating an integrated waste-to-energy process under a DOE work-for-others (WFO) agreement with FATER, an Italian JV between Procter & Gamble and the Angelini Industrial Group.

Key outcomes indicate that post-consumer absorbent hygiene products (AHP) can be readily and economically converted — without using harsh or expensive pretreatment routes — to fermentable sugar intermediates as well as biofuel and bio-based chemical products.

Biofuels that are produced from biobased materials are a good alternative to petroleum based fuels. They offer several benefits to society and the environment. Producing second generation biofuels is even more challenging than producing first generation biofuels due the complexity of the biomass and issues related to producing, harvesting, and transporting less dense biomass to centralized biorefineries. In addition to this logistic challenge, other challenges with respect to processing steps in converting biomass to liquid transportation fuel like pretreatment, hydrolysis, microbial fermentation, and fuel separation still exist and are discussed in this review. The possible coproducts that could be produced in the biorefinery and their importance to reduce the processing cost of biofuel are discussed. About $1 billion was spent in the year 2012 by the government agencies in US to meet the mandate to replace 30% existing liquid transportation fuels by 2022 which is 36 billion gallons/year. Other countries in the world have set their own targets to replace petroleum fuel by biofuels. Because of the challenges listed in this review and lack of government policies to create the demand for biofuels, it may take more time for the lignocellulosic biofuels to hit the market place than previously projected.

This work presents a detailed analysis of the production design and economics of the cellulosic isobutanol conversion processes and compares cellulosic isobutanol with cellulosic ethanol and n-butanol in the areas of fuel properties and engine compatibility, fermentation technology, product purification process design and energy consumption, overall process economics, and life cycle assessment. Techno-economic analysis is used to understand the current stage of isobutanol process development and the impact of key parameters on the overall process economics in a consistent way (i.e. using the same financial assumptions, plant scale, and cost basis).

After steam pretreatment of lignocellulosic substrates the fermentation of the biomass derived sugars to ethanol is typically problematic because of both the generally low sugar concentrations that can be supplied and the presence of naturally occurring and process derived inhibitors. As the majority of the inhibitory materials are usually associated with the hemicellulose rich, water soluble component, this fraction was supplemented with glucose to simulate high solids, un-detoxified substrate to see if a high gravity/high cell consistency approach might better cope with inhibition. Several yeast strains were assessed, with the Tembec T1, T2 and Lallemand LYCC 6469 strains showing the greatest ethanol productivity and yield. The addition of supplemental glucose enabled the faster and quantitatively higher removal of hydroxymethylfurfural (HMF). High cell density could provide effective fermentation at high sugar concentrations while enhancing inhibitor reduction. A 77% ethanol yield could be achieved using strain LYCC 6469 after 48 h at high cell density. It was apparent that a high cell density approach improved ethanol production by all of the evaluated yeast strains.